[ios] fix badgetextview EGTest

The TextBadgeView need to be explicitly accessible. In addition,
it is better to use an identifier instead of label to validate.

Bug: 1100811
Change-Id: I5e4a58d177d62a0f69fb85d84d16bad60f444cc5
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2283900
Commit-Queue: Chris Lu <thegreenfrog@chromium.org>
Reviewed-by: Gauthier Ambard <gambard@chromium.org>
Reviewed-by: edchin <edchin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#787463}

ios/chrome/browser/ui/reading_list/text_badge_view.mm

@@ -63,6 +63,7 @@ const CGFloat kDefaultLabelHorizontalMargin = 8.5f;
     [self activateConstraints];
     [self setBackgroundColor:[UIColor colorNamed:kBlueHaloColor]];
     [self setAccessibilityLabel:self.label.text];
+    self.isAccessibilityElement = YES;
   }
   [super willMoveToSuperview:newSuperview];
 }

ios/showcase/text_badge_view/sc_text_badge_view_controller.mm

@@ -16,6 +16,7 @@
   [super viewDidLoad];
   self.view.backgroundColor = [UIColor whiteColor];
   TextBadgeView* textBadge = [[TextBadgeView alloc] initWithText:@"TEXT"];
+  textBadge.accessibilityIdentifier = @"TEXT";
   [textBadge setTranslatesAutoresizingMaskIntoConstraints:NO];
   [self.view addSubview:textBadge];
   // Center badge on screen.

ios/showcase/text_badge_view/sc_text_badge_view_egtest.mm

@@ -23,7 +23,7 @@ using ::showcase_utils::Close;
 // Tests that the accessibility label matches the display text.
 - (void)testTextBadgeAccessibilityLabel {
   Open(@"TextBadgeView");
-  [[EarlGrey selectElementWithMatcher:grey_accessibilityLabel(@"TEXT")]
+  [[EarlGrey selectElementWithMatcher:grey_accessibilityID(@"TEXT")]
       assertWithMatcher:grey_notNil()];
   Close();
 }